1. Field of the Invention
The present invention relates to a lens barrier mechanism for protecting the first lens of a lens system, as viewed from an object, such as a photographing lens system to prevent it from being scratched or damaged.
2. Description of the Related Art
Most recent lens shutter type cameras employ a lens barrier mechanism instead of a conventional lens cap for protecting the first objective lens, as viewed from an object, from being scratched or damaged. The lens barrier mechanism is integrally formed with the camera body or lens barrel, in front of the first objective lens as viewed from an object, and has at least one lens protecting blade which is inserted into and retracted from the photographing optical path to open and close a lens opening of a lens unit. In a lens barrier mechanism having a plurality of lens protecting blades pivoted about the same axis, it is necessary for each lens protecting blade to be positioned at its closed position and open position when the plurality of lens protecting blades close and open a lens opening, respectively. Hence, in addition to a member for supporting the plurality of lens protecting blades, a member for positioning each lens protecting blade must also be provided within a limited space, e.g., on a decorative plate on which a lens opening is formed at the center. This results in an increase in the cost of production. Moreover, it is necessary for the camera to have a space large enough to accommodate the above members. This results in an increase in the size of the camera.
In the case of a plurality of lens protecting blades pivoted about a common axis with the plurality of lens protecting blades aligned side by side along the photographing optical axis, when this plurality of lens protecting blades are driven to open and close a lens opening, it is likely that the blades will become worn by rubbing against each other, eventually creating too much play between the blades.